Power transmission device and motor unit

Abstract

A bearing device includes a gear portion and a gear housing that houses the gear portion and stores a lubricant therein. The gear housing includes a side plate extending in a direction intersecting the axial direction, a recess recessed from the side plate toward the other side in the axial direction, a saucer opened upward, and a groove including a shaft opening opposing the gear housing and a peripheral opening opened to the recess. The gear portion includes an output shaft rotatably supported by the gear housing via a bearing, and a first gear connected to the output shaft. The saucer includes an opposing surface opposing an outer peripheral surface of the first gear. The groove is inclined downward toward the peripheral opening and reaches the bearing, and the shaft opening of the groove reaches the saucer.

What is claimed is: 
     
       1. A power transmission device comprising:
 a gear portion that is connected to one side in an axial direction of a power shaft which rotates about a rotation axis extending along a horizontal direction; and 
 a gear housing that houses the gear portion, and stores a lubricant therein; wherein 
 the gear housing includes:
 a side plate at an end on another side in the axial direction and widens in a direction intersecting the axial direction; 
 a tubular recess that is recessed to the another side in the axial direction from the side plate, and opens to the one side in the axial direction; 
 a saucer that extends to the one direction in the axial direction from the side plate and opens upward; and 
 a groove on a surface of the side plate on the one side in the axial direction, includes a shaft opening opposing an inside of the gear housing, and includes a peripheral opening that opens to an inner peripheral surface of the recess; 
 the gear portion includes:
 a bearing that is at an end of the recess on the another side in the axial direction; 
 an output shaft that extends along the rotation axis, and is rotatably supported by the gear housing with the bearing interposed therebetween; and 
 a first gear that is connected to the output shaft; 
 
 
 the saucer includes an opposing surface opposing at least an outer peripheral surface of the first gear in a radial direction; 
 the groove is inclined downward from the opposing surface to the peripheral opening, and an end on the another side in the axial direction reaches the bearing; and 
 the shaft opening of the groove reaches the opposing surface. 
 
     
     
       2. The power transmission device according to  claim 1 , wherein
 the output shaft includes a differential; 
 the first gear is a ring gear of the differential; 
 a case of the differential is in the recess; and 
 a portion of an outer surface of the case opposes the groove. 
 
     
     
       3. The power transmission device according to  claim 1 , wherein an inner peripheral surface opposing the peripheral opening of the groove approaches the bearing as the inner peripheral surface is directed toward the other side in the axial direction. 
     
     
       4. The power transmission device according to  claim 1 , wherein an upper side edge of the shaft opening of the groove faces upward as the side edge is directed toward the one side in the axial direction. 
     
     
       5. The power transmission device according to  claim 1 , further comprising a guide that extends from a lower side edge of the shaft opening to the one side in the axial direction. 
     
     
       6. The power transmission device according to  claim 1 , wherein the saucer includes a protrusion that extends in a direction approaching the outer peripheral surface of the first gear from an upper end of the opposing surface. 
     
     
       7. The power transmission device according to  claim 6 , wherein the protrusion extends along an upper surface of an internal space of the gear housing. 
     
     
       8. The power transmission device according to  claim 6 , wherein a gap between a distal end of the protrusion and an upper surface of an internal space of the gear housing is larger than a gap between the distal end of the protrusion and the first gear. 
     
     
       9. The power transmission device according to  claim 1 , wherein the opposing surface is separated from a peripheral tangent of the first gear at a point where a line connecting a center of the first gear and a lower end of the opposing surface intersects an outer periphery of the first gear as the opposing surface is directed upward. 
     
     
       10. The power transmission device according to  claim 1 , wherein
 the gear housing includes a lid that covers one side of the axial direction of the side plate; 
 an end of the saucer on the one side in the axial direction is connected to the lid; 
 the lid includes an oil passage connected to the saucer; and 
 a portion of an upper surface of the saucer is below the oil passage. 
 
     
     
       11. A motor assembly comprising:
 the power transmission device according to  claim 1 ; wherein 
 the power source is a motor.